Introduction Single codestream OpenGIS GML in JPEG 2000 for Geographic Imagery Encoding Specification

24 Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved. Figure 4 — Packaging of GML for a single codestream The single “outer” association box contains a box-first which is a label box. This shall contain the label “gml.data”. The outer association box shall contain at least one additional association box containing GML instance data. This association box shall have a box-first that is a label box with the label gml.root-instance and an XML box. This XML box may only contain GML instance data for the following items: • Coverage description see Clause 6.1 and 7.1 • Metadata instances see Clause 6.2 and 7.2 • Annotation instances see Clause 6.3 and 7.3 • Feature instances see Clause 6.4 and 7.4 The box labelled gml.root-instance shall not contain XML schemas and shall not contain CRS nor units of measure dictionary instances. Any number of association boxes may follow the gml.root-instance box. Each of the association boxes, other than the gml.root-instance and gml.data boxes, shall have a label the box-first shall be a label box in each case. The value of the label is any value allowed by JPEG 2000 Part II. This label is used in references to the XML box content using the mechanism described in Clause 8.5. asoc “gml.data” Unique-name” ASOC … dictionary data label xml instance data xml label “gml.root-instance ASOC Unique-name” schema data xml ASOC label ASOC label Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved. 25 The GML Root Instance data for the single codestream case consists of a root GML feature collection that contains codestream specific feature collections as members. These nested GML feature collections are as shown in Figure 5. abc:RootFeatureCollection … gml:featureMember abc:SpecificFeatureCollection … gml:featureMember gml:RectifiedGridCoverage … gml:RectifiedGridCoverage gml:featureMember gml:featureMember gml:FeatureInstance1 … gml:FeatureInstance1 gml:featureMember gml:featureMember gml:FeatureInstance2 … gml:FeatureInstance2 gml:featureMember … abc:SpecificFeatureCollection gml:featureMember abc:RootFeatureCollection Image Metadata Associated Features and Annotation Figure 5 — Single codestream root instance data in XML Box The minimal structure for the Single Codestream = single image case is then as shown in Figure 6. Figure 6 — Minimal packaging of GML for a single codestream Note that the instance box SHALL contain the following: • GML Coverage Description, whose domain is a gml:RectifiedGrid . The instance box MAY contain zero or more of the following: • Coverage metadata. This SHALL be referenced by the GML metaDataProperty from the Coverage description. asoc “gml.data” instance data xml label “gml.root-instance asoc asoc label 26 Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved. • Image Annotations per the GML Annotation Schema described in Appendix A. Note that the instance box SHALL not contain dictionary definitions for Coordinate Reference Systems, nor for Units of Measure. If these are to be supplied then an additional dictionary box shall be provided as in Figure 4.

8.3 Multiple codestreams case

The multiple codestream encoding enables multiple image of the same or different type different geometry, different radiometry to be packaged in a single JPEG 2000 file. Stereo image pairs, triangulation blocks, orthoimagery with associated digital elevation models, and multi-source image assessment are examples of the use of multiple codestreams. The structure of the JPEG 2000 file for the multiple codestream case is shown in Figure Figure 7. asoc “gml.data” “unique-id” schema data xml ASOC “unique-id” ASOC … dictionary data instance data xml xml label label label “gml.root-instance ASOC label xml Figure 7 — Packaging of GML for multiple codestreams The single “outer” association box contains a box-first which is a label box. This shall contain the label gml.data. The outer association box shall contain at least one additional association box containing the GML associated to each codestream. This association box shall have a box-first that is a label box with the label gml.root-instance and an XML box. The gml.root-instance XML box SHALL contain the following: • Coverage description for the associated codestream that uses a gml:RectifiedGrid domain see Clause 6.1 and 7.1. The gml.root-instance XML box MAY contain zero or more the following: • Coverage metadata. This SHALL be referenced by the GML metaDataProperty from the Coverage description. Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved. 27 • Image Annotations per the GML Annotation Schema described in Clause 9. • Associated geographic features expressed as GML features The box labelled gml.root-instance shall not contain XML schemas and shall not contain CRS nor units of measure dictionary instances. Any number of association boxes may follow the gml.root-instance box. Each of the association boxes, other than the gml.root-instance and gml.data boxes shall have a label the box-first shall be a label box in each case. The value of the label is any value allowed by JPEG 2000 Part II. This label will be used in references to the XML box content using the mechanism described in Section 8.5. The GML Root Instance data for the multiple codestream case consists of nested GML feature collections as shown in Figure 8.